The Obama administration, frustrated with the lack of willingness from the European Union to implement new, harsh sanctions on Russia, reportedly is considering going it alone and implementing unilateral sanctions.

But as border tensions build up again between Russia and Ukraine, President Barack Obama may find himself forced to choose between two unseemly options: wait for the EU to act in concert with the U.S., which is unlikely, or break from the coalition and throw out its current strategy of punishing Russian President Vladimir Putin.

If the U.S. moves to impose new, expanded sanctions by itself, it would be unwise, Eurasia Group President Ian Bremmer told Business Insider. The move would be a significant shift from the Obama administration's calculus thus far — a move that would signal a "weaker hand" going forward. It also would double down on a policy U.S. officials have admitted hasn't deterred Putin's actions in Ukraine.

"The Obama administration has consistently said that the U.S. was working to 'isolate' the Russians if they didn’t back down on Ukraine," Bremmer told Business Insider in an email. "It's unclear to me how unilateral sanctions supports that strategy.

"Russia's already ignored joint U.S.-EU sanctions, pressing ahead with escalation in Ukraine. America losing the Europeans only shows a weaker hand. If the U.S. is going to back off of what’s been a failed policy, better to do it earlier (and with their allies) than down the road."

The Pentagon said Wednesday that Russia was again building up its troops along the border, and the U.S. has in recent days accused Russia of continuing to send tanks and other weapons to help struggling pro-Russian separatists. Furthermore, the State Department claims Kremlin officials are allowing troops from the "Donetsk Peoples’ Republic" to establish a recruiting office in Moscow.

Ukraine on Tuesday also accused Russia of having a role in two airstrikes over the past two days.

Leaders of the EU are meeting Wednesday to discuss expanding sanctions on Russia. But even if they do, they are expected to be far short of what the Obama administration wants to impose — the "sectoral" sanctions that would punish certain areas of the Russian economy, like defense and energy. EU members have a much closer economic relationship with Russia, however, and they fear any far-reaching economic sanctions could boomerang and hurt their own economies.

Some members of Congress have argued new sanctions should have come sooner rather than later, saying the administration is putting its credibility on the line by continuing to threaten "costs" but not yet following through.

"The Ukrainian people are willing to risk their lives to defend their country against Putin’s aggression, but the Ukrainian government desperately needs assistance," Sen. Kelly Ayotte (R-N.H.) said Monday amid reports of escalated Russian troop levels along the border.

"Each new warning and speech from President Obama has barely elicited a shrug from Putin as he has continued to support separatists, send troops to the Ukrainian border, and conduct covert military operations in Ukraine."

An Obama administration official declined to comment on the sanctions being considered or the possible timing of those sanctions.